2781855 has 12 divisors (see below), whose sum is σ = 4821960. Its totient is φ = 1483632.

The previous prime is 2781853. The next prime is 2781887. The reversal of 2781855 is 5581872.

It is not a de Polignac number, because 2781855 - 2¹ = 2781853 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2781853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30865 + ... + 30954.

It is an arithmetic number, because the mean of its divisors is an integer number (401830).

2^2781855 is an apocalyptic number.

2781855 is a deficient number, since it is larger than the sum of its proper divisors (2040105).

2781855 is a wasteful number, since it uses less digits than its factorization.

2781855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61830 (or 61827 counting only the distinct ones).

The product of its digits is 22400, while the sum is 36.

The square root of 2781855 is about 1667.8893848214. The cubic root of 2781855 is about 140.6408545087.

The spelling of 2781855 in words is "two million, seven hundred eighty-one thousand, eight hundred fifty-five".